Online video advertising is an untapped goldmine, so thinks 24-year-old serial entrepreneur Emi Gal. His company, Brainient, is barely two years old and has built up a not-insignificant run of momentum

At nearly six years old, Muzu TV isn't the new-kid-on-the-block company in online video sharing. But it's chief executive and co-founder, Ciaran Bollard, wants to be turning over £100m in revenue before the company reaches 10 years old

Until the launch of Quilliant this month - say its creators - there has been no independent, UK incarnation of the book club online, somewhere aspiring writers can discuss and share their ongoing projects and improve their work. By Jemima Kiss

From the back of a fag packet idea in January this year to the launch on 11 May, Battersea-based Crowdity has already built a base of 35,000 active users and is aiming for 350,000 within a year. By Jemima Kiss

BubbleIdeas' two co-founders want to formalise feedback for enterprise and government - and they are doing it with a bootstrapped business headquartered in Singapore, developed in India and hosted in the US. By Jemima Kiss

We've profiled nearly 200 startups and early stage companies in our Elevator Pitch column since it began with a profile of Bragster in January 2008. And after a spell in rehab, some business botox and some entrepreneurial exfoliation, the pitch is back. By Jemima Kiss

Didiom is doing something new in the digital music space, offering a mobile service that streams your music collection from your home library - with the added twist that users can choose to 'bid' for music by offering a price they think is fair. By Jemima Kiss